A conventional nozzle mounted in a knitting machine is shown in FIG. 4 comprising a U-shaped fastening block 1 comprising a top 11, a bottom 12, an inlet hole 14 through the bottom 12 in communication with an external air compressor, a bore 16 through top 11 aligned with inlet hole 14, a stop member 65, an abutment member 61, a sleeve 6, a screw 62, a spring 63, and an adjusting cap 64 wherein elements 65, 61, 6, 62, 63 and 64 are provided in bore 16 from bottom to top; a female fastening member 2 on the vertical side of U-shaped fastening block 1; a sliding block 3 on the open side of U-shaped fastening block 1 and comprising a through inlet channel 31 in communication with inlet hole 14; a male fastening member 4 extended from side of sliding block 3 corresponding to female fastening member 2; and a block member 5 on the top of sliding block 3 and having a V-shaped groove 51 and an aperture 52 on the V-shaped groove 51 being in communication with inlet hole 14 and inlet channel 31.
In blowing operation, yarn is first placed on V-shaped groove 51. Then engage male fastening member 4 and female fastening member 2 to mount sliding block 3 in U-shaped fastening block 1 wherein inlet hole 14, inlet channel 31, and aperture 52 are in communication one another. External high pressure air is directed to blow yarn through inlet hole 14. As to the cleaning of block member 5, it is simply required to disengage male fastening member 4 from female fastening member 2 prior to removing sliding block 3 from U-shaped fastening block 1. However, the previous design suffered from several disadvantages. For example, the elements provided in bore 16 are complicated. Further, arms 42 of male fastening member 4 tends to break or malfunction after a long time of use (i.e., engaging with female fastening member 2 by pressing the arms 42). Furthermore, the assembly is complex and the manufacturing cost is relatively high.